A new antiserum prepared in rabbits to dialyzed proteins from calf corneal epithelium was compared to the antiserum previously reported for sheep in regard to the specificity of its immune reactions. The immune serum raised in sheep formed one precipitin line while immune serum from rabbits appeared to produce two lines when tested against the epithelial layer of calf cornea on separate Ouchterlony plates that contained calf serum. Although both antiserums exhibited antigen-antibody reactions with calf corneal stroma, only the rabbit antiserum reacted with endothelial layer of the cornea. Immune serum prepared in rabbits in contrast to that from sheep was found capable of cross reactions with soluble extracts of epithelium from lamb and hog corneas as well as corneal homogenates from rat, cat, monkey but not rabbit. The antigen for sheep in calf corneal epithelium was demonstrated to be identical with one of the two antigens for rabbit through the use of polacrylamide gel electrophoresis followed by immunodiffusion of the appropriate antiserum against the unstained gel. The technique of immuno disc electrophoresis also revealed that the second precipitin line observed when rabbit antiserum was tested with calf corneal epithelium on an Ouchterlony immunodiffusion plate was in reality two immune proteins with almost identical electrophoretic mobilities.